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Arterial pressure-volume relation and augmentation index

Posted on:2010-07-14Degree:M.SType:Thesis
University:Rutgers The State University of New Jersey - New BrunswickCandidate:Pitt, Ronald AndreFull Text:PDF
GTID:2444390002480994Subject:Engineering
Abstract/Summary:
Hypertension is the primary precursor to all forms of heart disease which according to the CDC continues to be the leading cause of death in the USA. A strong correlation between arterial stiffness and hypertension has been established. Similarly, a decrease in arterial compliance has been shown to be a major causative factor associated with hypertension. Consequently, many studies are designed to identify markers of the health of the arterial system. These markers have not been adequately defined.;To identify possible markers for quantifying arterial properties in hypertension, this thesis evaluates several popular methods for aortic compliance determination from measured aortic pressure and flow waveforms, and then establishes arterial pressure-volume relations as well as proposing new augmentation indices and comparing them with existing ones.;Simultaneously measured aortic pressure and flow waveforms were obtained from experiments performed on anesthetized mongrel dogs during control, methoxamine-induced hypertension and nitroprusside-induced vasodilation. Digitized data sets were analyzed based on hemodynamic equations established for arterial pressure-volume relation, arterial compliance and augmentation indices.;Results obtained highlighted the consistency in accuracy of the pressure-dependent compliance in predicting the aortic blood pressure. The average gradient of the volume-pressure decreased under hypertensive conditions indicative of the decreased compliance. The comparison of augmentation indices revealed that the most popular method actually produced the least significant distinction between the three conditions. However, all methods produced satisfactory ANOVA results (P < 0.001) for separation of means in differentiating control from hypertension and subsequent vasodilation.
Keywords/Search Tags:Arterial, Hypertension, Augmentation
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